Watch: Everything We Know About Pluto in One GIF

Over the course of New Horizons’ nearly decade-long journey to Pluto, mission scientists at NASA, Johns Hopkins, and the Southwest Research Institute have watched the icy rock grow from mere pixels into a real place, with topography and geology and all the things you’d expect from a planet (even though it technically isn’t one).

Today, after the space probe completed its closest approach to Pluto’s system, the New Horizons team released a new image—the most detailed ever—that shows mountains on the dwarf planet’s southeastern hemisphere. NASA’s Goddard Space Flight Center posted this timeline of Pluto photos, making the accomplishments of the New Horizons team that much more visceral. Take it all in.

Remember how excited you were last summer? No, not because you found a booth at the state fair selling deep fried beer. I’m talking about New Horizons, sillies.

Well get ready for another bout of excitement, because NASA has greenlit New Horizons’ next target: a lump of rock out in the Kuiper Belt called 2014 MU69. And don’t worry if you’re still exhausted from last year’s Pluto-brations (or the Juno mission’s orbital insertion happening this July 4th). New Horizons isn’t scheduled to rendezvous with 2014 MH69 until January 1st, 2019, so you have plenty of time to get ready. Because what better way is there to spend your New Years’ hangover than sitting in the dark and waiting for a space probe five and a half billion miles away to send a few squawks home confirming that it passed its target successfully?

But wait, you ask. Doesn’t this 2014 MU69 character sound familiar? It should. Nineties kids will remember that in season three of Big Bad Beetleborgs, a cyborg monster called 2014 MU69 kidnaps Flabber, leading Drew, Jo, and Roland on a wild chase through the Hillhurst suburbs. Just kidding, everyone knows that show only had two seasons. 2014 MU69 should really only sound familiar to Pluto-heads who were paying attention last August when NASA first announced the Kuiper Belt object as New Horizons’ next target. So what is new? Well, this is NASA just doubling down, saying it has allotted funding to the mission. Yay, money!

Pluto May Have Ice Volcanoes, and New Horizons Got a Peek

Two of Pluto’s mountains, Wright Mons and Piccard Mons, could actually be ice volcanoes. The blue points in the middle of each circle indicate a dip in elevation. NASA/JHUAPL/SWRI

Today, the New Horizons team dropped some science from an unfamiliar location. I mean, yes, all its results are coming from the Pluto system, but today Alan Stern & Co. presented this mountainous map at the annual meeting of the American Astronomical Society’s Division of Planetary Sciences. And it looks…kind of familiar.

The blue spot in the middle of the informally-named Piccard Mons and that belly button-looking depression in neighboring Wright Mons are areas of low elevation. And on Earth, that kind of hole in the middle of a mountain only means one thing: volcano.

OK, we get it. New Horizons was a complicated mission. One does not simply walk onto Pluto, right? Ooh! Wait! I got it. Ring of mountains? Volcano in the middle? It’s Mordor!

Now, sure, these volcanoes are really only maybe-volcanoes, because Pluto is, like, really far away, man. And so it’s hard to tell exactly what’s going on. If they are volcanoes, they won’t be spewing magma or lava bombs. These would be cryovolcanoes. Ice vulcanism! The New Horizons team thinks that these structures could have formed when a slurry of water ice, nitrogen, ammonia, or methane erupted from beneath the dwarf planet’s surface. The One Ring wouldn’t dissolve into steaming fizz; it’d freeze and crackle into shards. Which would be cool. Whatever works, right?

As for this video of Pluto’s wobbling, bobbling, precessing moons? Yyyyyeah. Pluto’s moons have super-weird shapes, which might be why they orbit like drunk college kids circling that one bar that doesn’t card. Or it could be that Charon, the biggest moon, exerts extra pull on all the smaller ones. Either way, don’t stare too long.

Charon’s Organa Crater Glows With the Force … Er, Ammonia

NASA/JHUAPL/SwRI

Not so long ago, on the far away moon of Charon, a tiny space probe spied a strange energy signature emanating from a crater named after Luke Skywalker’s sister. No, it wasn’t midi-chlorians. Organa crater, named for Star Wars heroine Princess Leia, is actually coated with ammonia, though scientists are still baffled as to why.

Ammonia is pretty abundant in the galaxy. Because it stays liquid at very low temperatures, many scientists believe it is behind a lot of the geologic activity on icy worlds like Charon. In fact, based on telescope observations from Earth and photographic evidence of geomorphology taken from New Horizons, scientists expected the faraway moon to be covered with the stuff. “But we haven’t seen it everywhere. This crater is an exception,” says Will Grundy, astronomer at Lowell Observatory in Arizona and ice expert for the New Horizons mission.

The source of the ammonia is a mystery, but Lowell and his co-investigators shared a few hypotheses. “One speculation is that this is just a more youthful crater than the rest,” says Grundy. In this scenario, ammonia would be everywhere under the top layer of Charon’s surface. Organa could be so young that space radiation hasn’t yet destroyed the underlying ammonia exposed by the initial meteor strike. “But we really don’t know the timescale at which that happens,” says Grundy.

Another idea is perhaps the meteor that created Organa crater was ammonia-rich, and left some of the stuff behind. The final speculation is that Organa is roughly the same age as other Charonian craters, but happens to be located over an unusually rich subsurface smear of ammonia. “But these are all pretty speculative, and I’m not sure if it’s useful to weigh one over another,” says Grundy.

Grundy says with better imagery the New Horizons team could probably tease out some clues from the geomorphology surrounding the crater, but that’s not likely to happen. New Horizons was three times as far from Charon as Pluto during the flyby. “We’re never going to get as high a resolution as we have with Pluto,” says Grundy.

Organa’s ammonia signature is even more striking compared to a nearly identical crater to the south, called Skywalker. As of press time, there was no indication that the sibling craters had ever accidentally kissed.

Fly Over Charon, Pluto’s Biggest Moon

Like Pluto, Charon is not a planet. But who needs recognition from the stuffy, earthbound International Astronomical Union? Especially when you’ve got ice volcanoes?

That’s right, ice volcanoes. See, Charon’s two hemispheres are so different that scientists’ best guess for why one is so much smoother is that ice erupts from below the dwarf moon’s surface. Bordering the the slick lowlands is a massive canyon system, which you can see in the video above.

The flight begins high above Mordor, which is what Charon-ologists have named the dark spot in the moon’s polar highlands. New Horizons’ atmospheric scientists believe that Mordor might actually be nitrogen deposits captured from Pluto (which is constantly shedding the stuff).

Then the flight swoops into the canyons, a system that seems to extend at least 1,000 miles. The canyons might even completely encircle Charon—sort of like the hug the moon deserves from those meanies at the IAU.

Watch: Pluto’s Sunset as Seen by New Horizons

It’s only been two months since New Horizons whizzed past Pluto, some 4.7 billion miles from Earth. Now, the space probe is in the process of sending back tens of gigabits of data collected during the flyby, including increasingly kick-ass photos of the icy rock’s surface.

The most recent images released by NASA show the dwarf planet backlit by the sun, revealing mountain ridges and atmospheric haze—lots and lots of haze. They also offer a more detailed look at Sputnik Planum, the smooth, icy expanse that looks like a big heart. Enjoy, and keep coming back for more photos—they’ll keep coming in over the next year.

New Photos of Pluto’s Haze, Backlit and In Glorious Detail

Slide: 1 /of 6.Caption: Caption: Just after it whizzed past Pluto, New Horizons took this photo of the dwarf planet backlit by the sun. The image shows mountain ridges and atmospheric haze—lots and lots of layers of atmospheric haze.NASA/JHUAPL/SWRI

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Slide: 1 /of 6Caption: Caption: Just after it whizzed past Pluto, New Horizons took this photo of the dwarf planet backlit by the sun. The image shows mountain ridges and atmospheric haze—lots and lots of layers of atmospheric haze.NASA/JHUAPL/SWRI

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If you ever even for a minute thought Pluto was an inert little ice ball, banish those thoughts now. A whole new batch of Pluto photos from New Horizons has some of the best views yet of the planet’s atmosphere and exotic ices.

A geeky aside: These new photos come from MVIC, a camera that’s part of Ralph, New Horizons’ main “eyes” and color imager. The last batch of New Horizons photos was from a different instrument, the Long Range Reconnaissance Imager or LORRI, which as its name implies was built for looking at Pluto from far away. With Ralph today, we’re getting up close and personal with Pluto.

And you know what scientists are super excited about seeing with Ralph? Atmospheric haze. Just as the Earth has fog and clouds and a water cycle, Pluto appears to have a nitrogen cycle. A bright spot, informally dubbed the Sputnik Planum, is probably covered in these exotic nitrogenous ices. And those swirls? Nitrogen glaciers. Looking good, Pluto.

In the best LORRI image we have down yet we could say there were "more than five" layers. In this MVIC image we can see many, many more.

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They’re here! Last Saturday, New Horizons started the intensive process of sending data from its July flyby of the Pluto system back to Earth. During its closest approach—about 7,800 miles from Pluto’s surface—the spacecraft collected tens of gigabits of data. That includes photos, spectra, and atmospheric readings. Now that data is coming back bit by bit.

Like, literally. The probe is so far away that it can only send data at a rate of around 1 to 4 kilobits per second. The probe has been sending back lower data-rate information from its energetic particle, solar wind and space dust instruments since late July, but Saturday marked the beginning of a new, year-long download of hi-res images and the like.

That should be plenty of time to clear the hard drives before New Horizons does its next flyby. Did you hear? The little probe will reach Kuiper Belt Object 2014 MU69 in January 2019.

Something Deep Inside Pluto Is Replenishing Its Atmosphere

NASA/JHUAPL/SwRI

Pluto has a problem: Its thin, nitrogen atmosphere shouldn’t be there. Ultraviolet rays from the sun should have knocked it away, molecule by molecule, in the dwarf planet’s first few thousand years. Four billion years later, Pluto’s atmosphere is still there, a gauzy interplanetary mystery.

Okay, it’s really scientists who have the problem, because it’s not like there are nitrogen-breathing Plutonians down there pacing worriedly over impending suffocation. Right, NASA? Right?!? No, all worrying has been purely academic, expressed in papers like the one published earlier this month by a pair of New Horizons scientists who examined the trio of prevailing theories behind the atmosphere’s perplexing replenishment.

High noon on Pluto looks like dusk on Earth. But even that small amount of solar energy is enough to turn frozen nitrogen on Pluto’s surface into gas. Once aloft, Pluto’s gravity is too weak to keep the particles from being blown away by ultraviolet radiation. (In case you’re wondering, Earth’s mass is enough to keep its atmosphere mostly safe from getting blown off into space.)

Pluto has been around for about four billion years, and according to the best math, it should have lost about 7,000,000,000,000,000,000,000 grams of nitrogen (give or take a zero) since then. But scientists currently estimate that the planet has about 30,000,000,000,000,000 grams of nitrogen atmosphere, and loses about 1,500,000,000,000 grams each year. “Basically, it would take only a few thousand to tens of thousands of years to lose that atmosphere,” says Kelsi Singer, post-doctoral researcher at the Southwest Research Center and co-author of the paper. Basically, that’s not a very long time.

Considering that Pluto has been around for more than four billion years, the odds are pretty friggin’ slim that humans would meet the dwarf planet during its brief phase of atmosphere-having. No, something is replenishing the supply. Scientists, you got some ‘splaining to do.

There are two basic mechanisms for resupplying Pluto’s atmosphere: “You can either bring stuff in from the outside or bring stuff up from the inside,” Singer ‘splains. Comets are a handy mechanism for both categories, as they can deposit nitrogen when they impact, or punch holes through the surface to expose quantities of the frozen gas. Singer is an impact expert, so she did the calculations for how much nitrogen a comet would shed, or dig up, upon impact. Her co-author Alan Stern, studies atmospheres (amongotherthings) and ran the numbers for gas loss. But even with their most conservative estimates—the maximum number of comets, the deepest of impact craters—nothing from off planet could cover the deficit of nitrogen loss.

Instead, they offer that the nitrogen is being replenished through more conventional geologic activity like cryovolcanism or tectonic action. But nobody yet knows what is behind this geologic churning, as Pluto is too small and too old to be holding much remnant energy from its formation. It’s also too far from any planetary body that would be large enough to tidally churn its innards. Something else inside the dwarf planet was causing exhalations. Does a Great Old One stir under the dark equatorial region, ominously nicknamed Cthulhu Reggio? It would explain the Sleeper of R’lyeh’s long absence…

Perhaps wisely, Singer and Stern do not explore that chilling hypothesis.

The most likely battery for Plutonian heat are huge chunks of uranium or potassium wedged in its rocky core. “Those will emit heat as they break down, and the heat has to go somewhere, so it causes local melting,” says Will Grundy, a planetary scientist, ice expert, and French cheese connoisseur at Lowell Observatory in Arizona.

The authors submitted their paper back in May, just as New Horizons was sending home its first images of Pluto. Since then, the probe’s cornucopia of data has supported Singer and Stern’s geologic hypothesis. “We do seem to be seeing a good deal of recent geologic activity on Pluto, so that’s not a bad sign for our paper,” says Singer. Things will look even better come September and October, when they can make better estimations of the impact rate based on the lossless data showing the dwarf planet’s craters. “We also get data from particle and plasma, that will help us calc the rate of atmospheric escape,” she says.

And every bit that arrives will blow away the mystery of Pluto’s missing molecules.

The Ices on Pluto’s Surface Are Totally Nuts

NASA/JHUAPL/SWRI

Earthlings have a sadly unsophisticated view of ice. Terrestrial types mostly think about it in terms of water ice—solid, cold, slick to the touch as it begins to melt in their warm, fleshy hands. But not Plutonians. If you lived on Pluto, you’d have as many names for ice as the Eskimos have for snow: words for carbon monoxide ice, nitrogen ice, and methane ice, all with different properties.

Today’s photos back from New Horizons put the spotlight on those frozen solids. In this top false color image, you can see just how much compositional variety defines Pluto’s surface—from the bright white of the carbon monoxide ice in the middle of Pluto’s “heart,” now officially called Tombaugh Regio, to the bands of colors likely created by the seasonal transport of ices from equator to pole. The blueish spots might be ices that have traveled from the left lobe of Pluto’s heart.

And then there’s the ice’s geological activity. “Water ice at Pluto’s temperatures won’t move anywhere,” says New Horizons co-investigator Bill McKinnon. “But these ices are geologically soft and malleable, even at Pluto conditions.” In new high-resolution images from the LORRI camera, scientists can see the flowing solids—including nitrogen ice—in the vast Sputnik Planum interacting with towering mountains, flowing between them and even filling in old impact craters.

NASA/JHUAPL/SWRI

“We knew there was nitrogen ice on Pluto, but to see evidence for recent geological activity is simply a dream come true,” says McKinnon.

Watch: Fly Over Pluto’s Icy Mountains With New Horizons

If the first close-up images of Pluto’s mountain ranges sent home by New Horizons seemed a little underwhelming, it might have been because you couldn’t really get a sense for their scale in a two-dimensional photo. Now NASA has released an amazing simulated video of the space probe’s flyover, helping those features pop out like they should.

Those mountain ranges have a name now: Norgay Montes, named after one of the first people to summit Mount Everest, Tenzing Norgay. Some of the peaks seen in this flyover are up to 11,000 feet tall—an impressive stat on its own, but especially so when you consider they’re probably made of ice (the frozen nitrogen and methane that covers most of Pluto’s surface would collapse under themselves at that elevation).

The video continues and transports you to the so-called Sputnik Planum, a vast plain of unexpectedly craterless surface that suggests Pluto is geologically quite young (if you can call 100 million years old young). The plain lies within the region now officially named Tombaugh Regio, after Pluto’s discoverer—but to us, it’ll always be Pluto’s heart.

The Many Ices of Pluto’s Surface, in Living Color

NASA/JHUAPL/SWRI

Today the New Horizons team treated the world to new images of Pluto, Charon, and Hydra, all taken by LORRI, New Horizons’ main imager. But LORRI’s all grey. Still to come are images featuring the full visible light spectrum, plus near infrared from RALPH, the probe’s color and infrared imager.

Nothing new from RALPH just yet, but as a tease of what’s to come, New Horizons’ planetary ice expert Will Grundy, of the Lowell Observatory, showed off some methane readings that were sent over in the probe’s final broadcast before it went dark for its July 14 flyby.

The bright blue, red, and black pixels—overlaid on a LORRI basemap—represent methane ice accumulations. These colors represent data from just three of RALPH’s 256 infrared wavelengths. As such, they don’t say much more than that Pluto has different types of ice. “All I’m showing is the diversity of terrains,” says Grundy.

But there are some interesting clues. For one, Grundy says that the colors in the ice cap look a lot like the colors in the right side of the giant heart—which today New Horizons informally named the Tombaugh Regio after Pluto’s discoverer, Clyde Tombaugh. “The ices do have distinct properties, different melting points,” Grundy said at an earlier conference, speaking more generally about Pluto’s surface.

All vague, all tantalizing, and taken in context with some of the other news revealed today—that Pluto has massive mountains made of water ice and could be geologically active—these slim details hint at big things to come.

Pluto may be cold, small, and far away, but the world is anything but dull.

Charon Comes Into Focus in New Horizons’ Latest Photos

Maybe you still haven’t figured out how to say the name of Pluto’s largest moon. Let me help. It’s pronounced “WOW.”

I don’t want to interrupt your gasping with too many words, but here are some quick stats on the shot.

Draw your eyes to the dark area around the moon’s north pole. “Informally we’ve been referring to that as Mordor,” says Cathy Olkin, one of the mission’s top planetary scientists, to the delight of everyone. Trace your gaze down the right curve until you reach a notch, at about the 2 o’clock spot. That’s a canyon. A big one, about four to six miles deep.

And that’s not all. Move your eyes down and in and follow the huge sash of canyons banding across the planet’s middle. This is about 600 miles across, and according to Olkin could be the result of internal processing. That’s right, active geology.

Just as with similar details on Pluto, the team’s speculations about what is causing this geology are so far guarded and vague.

But what’s certain is that “something is making these two worlds very, very different,” says Alan Stern, the mission’s principal investigator. Pluto is covered in water ice, Charon has massive cliffs. But the shroud of mystery that covers both is being steadily removed.

Everybody, Meet Hydra, Pluto’s Outermost Moon

In Greek mythology, the hydra was a many-headed dragon snake with regeneration powers. That’s impressive, but I’m pretty sure that its namesake moon has officially eclipsed its forbearer.

“Pluto and Charon are going to steal the day today, but let’s not forget that Pluto has four small moons as well that we want to collect data on,” says New Horizons project scientist Hal Weaver. “This morning, we got the first really well-resolved images of Hydra.”

Prior to this image, the best pictures of Hydra looked like someone took a quick pass of an eraser over a pencil-drawn period. By comparison, each pixel in the relatively crisp little nugget above represents two miles.

The cool thing about Hydra is how much we have to learn about it. Before today, Hydra was square. Now we can finally see its shape, a wobbly sort of potato-looking thing. We also know its size: 28 by 19 miles across. “New Horizons makes it easy for us,” says Weaver. “Just count the number of pixels across.”

And there’s plenty more to come.

As New Horizons floods its team with data, they will learn more about its composition and will develop clues about its origins. Combined with data from the other four moons and Pluto itself, that data will help scientists pull together an origin story for the tiny planetary system.

What If Pluto Suddenly Disappeared?

It is less than three hours until New Horizons’ safe and sound message arrives—or doesn’t. Worrier that I am, I’m still worried that the brave little probe might run afoul of a dastardly space pebble. But there’s something else that’s also been nagging me: What if Pluto suddenly disappeared?

It’s a question with long odds—much more improbable than the 1 in 5,000 chance of collision Alan Stern mentioned this morning—and let’s face it, pretty silly. But I still found some experts to scratch my itch.

Specifically, I’m curious about the gravitational effects. Would we feel it on Earth? “If Pluto disappeared, it certainly wouldn’t have an effect on Earth,” says Sarah Hörst, a planetary scientist at Johns Hopkins University. Gravity depends on mass, and the force it exerts decreases over distance. Pluto is too tiny, and too far, to affect Earth. And Mars. And Jupiter. And Saturn, Uranus, and Neptune.

Pluto is so tiny compared to everything else that pretty much only its moons would notice if it disappeared. “Notice” meaning they’d shoot off into space.

In fact, even New Horizons wouldn’t really be affected. “There’s no magnetometer, and we’re not using any forces around the planet to trigger anything on board,” says Alice Bowman, New Horizons’ mission operations manager.

New Horizons’ flyby maneuvers are pre-programmed, so if Pluto suddenly disappeared all it would return are pictures of empty space. And because the light from Pluto would disappear before New Horizons had sent its 4:27pm ET message home, any Earthly telescopes would get the news first.

Really, Here’s How You Pronounce “Charon”—Probably

The Charon name thing is starting to get to me. Every meeting, press brief, interview I hear the name of Pluto’s largest moon pronounced differently. I swear to Hades, sometimes I hear the same person pronounce it two ways. Granted, I’m jet lagged, sleep deprived, and the coffee in the press room is lukewarm and from Dunkin’ Donuts (what gives, NASA?), but I’m starting to feel like someone is messing with me.

So I started asking people—mostly people wearing black polos emblazoned with the nine-sided New Horizons logo: “How do you pronounce the name of Pluto’s largest moon?” I didn’t get far enough to get meaningful survey results, but I did find out why the results would always be mixed.

That’s because I ran into Will Grundy, one of New Horizons’ co-investigators and an astronomer at Lowell Observatory. “Well, the original Greek way to pronounce it would be Gheghron,” he says, shoving the word out of the back of his throat like it’s a big, fat Klingon loogie. Gross, but makes sense. After all, Charon was the ferryman who brought damned souls across the river Styx into Pluto’s realm. But the astronomer who gave the moon its name didn’t even know about the Greek myth when he picked the name1.

Jim Christy, who discovered the moon in 1978, had promised his wife Charlene he would name the object after her. See, his wife’s name is Charlene, so he took her nickname—Char—and threw an -on in on the end to science things up.

Some of his colleagues had been lobbying to name the moon Persephone (Pluto the god’s abducted queen), so he started doing some research. That’s when he stumbled across the Greek myth, and with that argument in hand the astronomical community informally adopted Charon later that year, and then formally in 1985.

So what’s that got to do with the pronunciation? Most astronomers, says Grundy, pronounce it “Share-on, as a tip of the hat to Jim and his wife.” But then he shrugs and says everybody flops back and forth all the time. “We all say it both ways in a single sentence.”

Really? Guys, that is a hell of a way to come up with nomenclature. Lunacy, even.

1 Update 14:26 ET July 20 2015. This Sky & Telescope article from 2008 has the entire naming episode in full detail.

NASA Releases Stunning Color Images of Pluto and Charon

NASA/JHUAPL/SWRI

Holy moly what a press conference we just had here at Pluto central. Alan Stern unleashed his science officers with new images and new science, and the first to drop were the highest resolution color pics of Pluto and Charon yet.

Each shows some pretty cool stuff. For Pluto, the biggest revelation is that the big heart is actually two different colors. Those colors (exaggerated for contrast) indicate different geologic, tectonic, or morphologic origins. And the rest of the visible world is a mosaic of patina. “Some regions are relatively ancient, and other places are very young and currently undergoing geologic evolution,” said Jeff Moore, the New Horizons team scientist from NASA Ames who presented the images.

But characteristic of the New Horizons team, Moore was guarded on the details. He said he’s waiting for stereographic data—which will show relief—before speculating any further on what might be happening on the dwarf planet’s surface. For instance, the heart’s left lobe currently looks as smooth as a cherub’s cheek, but some cratering might show up at higher resolutions.

The information from Charon is probably even more surprising. See that big blob of red? That stuff came from Pluto. “Charon does not have an atmosphere that is known so far,” says Will Grundy, a New Horizons team scientist and astronomer at Lowell Observatory. Charon may not have an atmosphere, but Pluto is leaking nitrogen like crazy. And as those nitrogen particles leave Pluto, Grundy says they could be getting dragged into Charon’s gravity. The distribution over the moon would be about even. But while nitrogen particles will burn away on the always-sunny equatorial and midlatitude regions, those that land on the polar night side are in the dark for decades.

If this hypothesis is correct, the chemical processes in the nitrogen would stain the underlying rock red. Grundy says he is waiting to see the other side of Pluto to see if that side is also red. “The prediction should say that the other pole looks really similar.”

Pluto Will Send Earth a Love Letter Tomorrow

NASA/JHUAPL/SWRI

Tomorrow, when New Horizons makes its historic flyby of Pluto, it will be focusing in on just one face of the dwarf planet. In this latest photo captured by the space probe’s black-and-white LORRI camera, you can see that face—defined by a large, bright heart-shaped feature—beginning to rotate into view.

Only the top half of the heart is visible on the left side of this image, but come tomorrow, New Horizons will capture the valentine in full. (Viewers will have to wait up to a day and a half to actually see the image, since the probe will be too busy collecting data to send it back to Earth immediately.)

Rotating out of view, on the other hand, will be a number of other interesting geological details. The last good look New Horizons got of Pluto’s far side came in on Saturday. And this image is the best astronomers will get of the bullseye-shaped feature (to the right) that might be an impact crater. Without better images, the New Horizons team may never know for sure.

Watch: Here’s What New Horizons’ Pluto Flyby Will Look Like

Nobody is going to see New Horizons fly through the Pluto system. At least, not in real time. But thanks to the power of planetary physics you can watch the space probe pass by on your computer right now. NASA’s awesome visualization team has loaded the flight plan into their Eyes On The Solar System app.

The video above shows 8 hours of the flyby, speeding by at 10 minutes per second. The inset window shows what New Horizons’ suite of instruments see (and which instruments are currently active). And those images are updated as new data comes in.

“That is the best map of Pluto, and if they release another one tonight we’ll update it immediately,” says Doug Ellison, a NASA visualization producer. Like the rest of us, he’s really anticipating that new imagery. “It will be nice to put a map on Charon, it always sucks to have these gray potatoes in space.”

But if you’re really antsy for some real time communications, Ellison recommends you fire up DSN Now. This tool shows active communications from all NASA spacecraft. No need to burn your retinas waiting for New Horizons to perk up. The first communications post-flyby are scheduled to arrive at 9:07pm ET on July 14.

NASA Finally Knows Pluto’s Size…Kind Of

At a press conference, New Horizons’ top dog Alan Stern just announced that his team has calculated Pluto’s most accurate diameter yet: about 1,473 miles from one end to the other, give or take 12 miles.1 You’d think this would be something NASA had nailed down by now, but it’s impossible to measure Pluto’s size without also knowing its distance from Earth.

That’s right: New Horizons is literally aiming for the unknown. The reason nobody knows Pluto’s exact location is because humans have only known about the planet for 85 years, which is about a third of the time it takes for Pluto to orbit the sun. The uncertainty is relatively small, but it affects all kinds of things.

Like the flight plan as New Horizons passes through the Pluto system. On Tuesday, New Horizons is programmed to rotate and focus its instruments on each of the dwarf planet’s moons in turn, and on the planet itself. If NASA’s estimate of Pluto’s distance is too far off, New Horizons will aim at blank spots in the sky.

Nobody here thinks there’s a huge possibility of missing the system completely, but some actually want the estimates to be a bit off. “Currently, as Charon rises from behind Pluto the camera is still looking at Pluto,” says Doug Ellison, a NASA visualization producer. On the Eyes On Solar System app, he showed me that if Pluto is a little bit closer than the scientists think, New Horizons will be perfectly placed to capture Charon rising behind it. “You hope for a little bit of uncertainty, because then you get that perfect Kodak moment,” he says.

This latest size estimate is slightly larger than what scientists had believed before, and it changes some other calculations. “It’s less dense, so that raises the question of the amount of ice in the interior,” says Stern. That’s because while Pluto’s size was up in the air, scientists have known the planet’s mass for a long time. A larger planet would mean less rock, more ice.

Ironically, scientists won’t get their best size and distance estimates until New Horizons passes through the system.

1UPDATE 1:18 ET 07/14/15: This story was updated to correct Pluto’s diameter.

Cliffs and Crater-Like Features Appear in Latest Pluto Shot

NASA/JHUAPL/SWRI

Let’s all take a second to appreciate the fact that this newest photo of Pluto was taken more than 1 million miles away from the icy dwarf planet. That’s how far away New Horizons will be tonight at 11:23 PM EST, on its way to an historic flyby on Tuesday morning.

You might be fooled into thinking Pluto and Charon look really similar, comparing this photo to the latest images of the big moon in the post below. But keep in mind that these images are uncolored, taken by New Horizons’ black-and-white LORRI camera. Once the team has the chance to add in color data from the Ralph camera, the differences between the planet and its moon become clear: Pluto is reddish-orange (not blue, like you might have thought), and Charon is more muted gray.

What’s really cool about these two is they are the only known planet/moon pair with a similar origin to Earth and its Moon. “This is the only other example of a giant impact planetary system,” says Alan Stern, New Horizons’ principal investigator. Of course the difference between the Earth system and the Pluto system being that the latter has many other moons in addition to Charon.

Pluto’s Biggest Moon Has a Personality of Its Own

NASA/JHUAPL/SWRI

At about half the size of Pluto, it isn’t really fair that Charon has to take a back seat to the dwarf planet that it nominally orbits. The two bodies actually form a binary planet system, orbiting around a common center of mass. So it’s pretty awesome to see Pluto’s biggest moon (it has five that astronomers know of) come into its own as New Horizons approaches and delivers better and better photos of its surface.

This latest image begins to show some of the same geological features that astronomers have been oohing and aahing over in snapshots of Pluto. Specifically, geologists on the New Horizons team are interested in the 200-mile-wide dark region at the moon’s northern pole, and a group of chasms and craters on its lower half.

Unlike Pluto, which is covered with some kind of snow, Charon’s surface is bare—it should be easy to read. “If you’re a pure hard rock geologist, all those snows are just in the way of studying the geology,” says Alan Stern, New Horizons’ principal investigator. For reference, the cut all the way to the right in the image above is longer and miles deeper than the Grand Canyon. Take that, Pluto.

NASA Doesn’t Care If Everyone Else Calls Pluto a Dwarf…

…They just call it interesting.

Hello from the Applied Physics Laboratory at Johns Hopkins University, mission control for the New Horizons mission, where Jim Green, NASA’s planetary science director just laid out the space agency’s take on Pluto’s status. In 2006, the International Astronomical Union reclassified the icy rock as a dwarf planet—a demotion in many astronomers’ eyes. But as Green says:

NASA’s position is quite simple: We do not care what we call this. It’s an object well worth observing.

In other words: When it comes to planetary science, size doesn’t matter.

New Horizons Gets Its Last Look at the Far Side of Pluto

NASA/JHUAPL/SWRI

As the New Horizons team continues its countdown to the space probe’s closest approach to Pluto on Tuesday morning, it continues to release snapshots of the icy rock. Today’s image, taken by the black-and-white LORRI camera, shows four evenly-spaced spots on the side that faces Charon, Pluto’s largest moon.

The team has seen these features before, but the extra detail in this shot is important to the mission’s Geology, Geophysics and Imaging team. Pluto and Charon are tidally locked, orbiting around a central point with the same faces always pointing toward each other. That means the dwarf planet’s spotted face will be turned away from New Horizons when it passes by; this is the last time the team will have a chance to see the spots up close.

New Horizons Scientists React to Geological Detail on Pluto

NASA/JHUAPL/SWRI

New Horizons is continuing on its path toward Pluto, falling through space at 31,000 miles an hour and giving viewers here on Earth increasingly detailed looks at features on the dwarf planet’s surface. The space probe was still 3.3 million miles away when it captured this image, but mission members are already getting excited about the geology coming into focus.

A region known as the whale’s tail is especially sharply defined in this latest photo. Both program scientist Curt Niebur and principal investigator Alan Stern expressed interest in the strong contrast between the darkness in the tail and the brighter grey area directly above it.

If you don’t buy that these details are a big deal, just check out these faces in reaction to the snapshot as it came in (Stern is to the left):

WIRED science writer Nick Stockton will be at Johns Hopkins Applied Physics Laboratory next Tuesday when New Horizons makes its closest approach; follow him at @StocktonSays for updates and hopefully more reaction shots just like that.

New Horizons’ Latest Image Reveals Features on Charon, Too

The bright spots on the bottom of Charon, to the left, might be impact craters. NASA-JHUAPL-SWRI

When New Horizons sent its first images of Pluto back after its glitch this weekend, there was much rejoicing. But the scientists in Maryland—a collection from Johns Hopkins Applied Physics Laboratory, the Southwest Research Institute, and NASA—only processed one fully-colored photo at first, and it only showed Pluto.

Now, they’ve taken the time to add color from New Horizons’ Ralph camera to another image taken by the high-detail LORRI camera, showing Pluto and its largest moon, Charon. And it reveals some amazing features on the satellite’s surface. (Click the photo to expand to its highest resolution.)

While Pluto stands out in striking red and orange tones, Charon is mostly brown and grey, with a few bright spots sticking out on its bottom surface. The mission’s Geology, Geophysics and Imaging team think that those spots might be impact craters—and if they are, they could provide a peek at what’s hidden beneath Charon’s surface. The best guess right now is that Charon is half rock, half water ice on the inside, but astronomers might get a closer look when New Horizons makes its closest flyby on July 14.

Follow New Horizons on Its Journey to Pluto and Beyond

It’s taken nine years to get there, but on July 14, 2015 the New Horizons spacecraft will finally fly by its destination. In this video, hear how the historic mission to Pluto happened from some of the people who helped launch it: principal investigator Alan Stern, co-investigators Marc Buie and Cathy Olkin, and principal engineer Tiffany Finely.

After Tuesday, the team’s work won’t be done: Because Pluto is so far away—five hours of light time away, to be precise—that means transporting all that crucial data from the spacecraft will take a while. “Our data rate to the spacecraft right now is one kilobit per second,” says Finely. “And with all of the data that we’re taking through the few days leading up to the Pluto flyby and then a few days afterwards, it’s going to take us a whole year to download all of that data.” Take that, Time Warner.

New Horizons Got Too Excited and Passed Out on July 4th

The New Horizons probe. NASA

Though it’s 2 billion miles away and on the wrong side of the sun, NASA’s New Horizons probe cast quite a shadow on 4th of July festivities. Just days from its rendezvous with Pluto, the spacecraft shut down, went into sleep mode, and briefly lost communication with ground control.

Exhale, it’s all good. About an hour after the tiny probe went dark, NASA reestablished communications. And the agency knows what went wrong. New Horizon’s central computer was gearing up for new observations while simultaneously compressing science it had already captured. All the activity overclocked its processor, so it went into sleep mode.

In other words, New Horizons got so excited it passed out. Don’t feel bad, little guy, we’ve all had a 4th of July like that. Read more here.

8-Bit Video Shows the Moon Charon Orbiting Pluto

NASA

NASA has released near-true color images of Pluto and the largest of its five known moons, Charon, captured by New Horizons. Stitched together, images from May 29 and June 3 make a jumpy video of the moon’s six-and-a-half day orbit.

Not impressed by these jerky blobs? Keep in mind that these pictures were taken more than 30 million miles away from Pluto’s surface, from two different perspectives. One video shows Pluto centered with Charon orbiting it, while the other depicts the pair orbiting their collective center of gravity (Pluto was demoted from planet status in 2006 partly because of Charon’s huge relative size—one-tenth that of the little rock).

“It’s exciting to see Pluto and Charon in motion and in color,” says Alan Stern, a planetary scientist at the Southwest Research Institute and principal investigator for New Horizons, in a NASA press release. “Even at this low resolution, we can see that Pluto and Charon have different colors—Pluto is beige-orange, while Charon is grey. Exactly why they are so different is the subject of debate.” Read more here.

Odd Orbits Deepen Pluto’s Mystery

An image taken on July 7, 2012 by the Wide Field Camera 3 on the Hubble Space Telescope shows the recently discovered fifth moon of Pluto. Moons P4 and P5 are now known as Kerberos and Styx, respectively. NASA, ESA, M. Showalter (SETI Institute) and L. Frattare (STScI)

Pluto is so far away that astronomers only discovered four of those orbiting bodies in the last decade (the largest, Charon, was discovered in 1978). New analysis of Pluto’s system, gleaned from Hubble Space Telescope images, suggests that three of the small moons—Styx, Nix and Hydra—are locked in close rotation. That keeps them from colliding as they circle the “binary planet” formed by Pluto and Charon.

But that alignment can be thrown into chaos thanks to interactions with those larger bodies and the recently discovered moon Kerberos. Astronomers Mark Showalter and Douglas Hamilton hope their findings, published in Nature today, will help explain how planets and their satellites form. Saturn’s cratered, potato-shaped moon Hyperion also has a wobbly rotation, one that is impossible to forecast in advance, unlike the majority of well-behaved, synchronously rotating moons in the solar system. Read more here.

Pluto’s First Color Portrait From New Horizons

April 9, 2015: The first color image of Pluto taken by the New Horizons spacecraft on approach. Nasa

NASA’s New Horizons spacecraft just sent back its first color image of the dwarf planet Pluto and its largest moon Charon. It’s a blurry glow taken by the craft’s Ralph color imager from 71 million miles away, but it’s a sight to behold nonetheless.

NASA launched New Horizons in 2006 to study Pluto and other objects in the Kuiper belt—the Solar System beyond Neptune, from about 2.5 to 4.5 billion miles from the sun. New Horizons already snapped some epic images of Jupiter back in 2006 and 2007. And on July 14, the spacecraft will fly past Pluto for an up-close-and-personal photo shoot.

The research team back at NASA hopes to use those shots to better understand the physical landscape and geography of the dwarf planet, including some features as small as a couple of miles. In the intervening weeks astronomical voyeurs can expect to see tons more images of Pluto and its moons taken while the spacecraft is on approach. Read more here.